A number of types of floating devices have been used or proposed for use with docks, platforms and the like. These have several disadvantages:
1. Metal drums can rust, leak and contaminate the water; they are heavy; PA1 2. Rigid foam can deteriorate over time and break up into small particles; PA1 3. Foam filled automobile tires are expensive relative to the amount of flotation capacity they provide. They are heavy. PA1 4. Plastic dock flotation systems are expensive, generally single purpose and not suited for building a structure upon. These are generally systems obliging the user to use all parts of the system.